Defining layer CRS and avoiding CRS dialog in PyQGIS?

Question

There is an existing Shapefile, which I want to add.

At the moment my code looks like:

self.iface.addVectorLayer(self.shpFilePath, "Track", "ogr")

It works fine, but i want to define the crs within the code. Is it possible? I found some similar questions like this one: Programmatically Select a CRS in QGIS 2.4 using Python

But i don't get it work anyway.

Answer 1

I solve the similar problem this way:

from qgis.core import *
from qgis.gui import *

layer = QgsVectorLayer(self.shpFilePath, "Track", "ogr")
crs = layer.crs()
crs.createFromId(4326)
layer.setCrs(crs)
QgsMapLayerRegistry.instance().addMapLayer(layer)

Answer 2

After months later I found a solution. You should add two lines before and end of the script which is from @Domokos Endre:

import os

iface.mainWindow().blockSignals(True)

layer = QgsVectorLayer(path, "My Layer",  "ogr")
crs = layer.crs()
crs.createFromId(32637)  # Whatever CRS you want
layer.setCrs(crs)

QgsProject.instance().addMapLayer(layer)
iface.mainWindow().blockSignals(False)

Answer 3

Based on both this blog post and the answer to How can I specify the CRS of a raster layer in pyqgis?, you can achieve what you want this way:

settings = QSettings()
# Take the "CRS for new layers" config, overwrite it while loading layers and...
oldProjValue = settings.value( "/Projections/defaultBehavior", "prompt", type=str )
settings.setValue( "/Projections/defaultBehavior", "useProject" )

# YOUR CODE TO LOAD THE LAYER GOES HERE

# ... then set the "CRS for new layers" back
settings.setValue( "/Projections/defaultBehavior", oldProjValue )

Note: If you're still using QGIS v2.x (BTW, you shouldn't :P), use the variable name "/Projections/defaultBehaviour" instead.

Answer 4

The following code should allow you to add a vector layer without the CRS popup window from appearing (atleast it doesn't appear for me):

from qgis import *
from qgis.utils import *

#replace "shapefile_path" with your layer's path; replace "Layer_name" with whatever name you want to give the layer in the TOC
qgis.utils.iface.addVectorLayer("shapefile_path", "Layer_name", "ogr")

#Use loaded layer as active layer to set the CRS
myLayer = qgis.utils.iface.activeLayer()
myLayer.setCrs(QgsCoordinateReferenceSystem(4326, QgsCoordinateReferenceSystem.EpsgCrsId))

#Sets canvas CRS
my_crs = core.QgsCoordinateReferenceSystem(4326, core.QgsCoordinateReferenceSystem.EpsgCrsId)
iface.mapCanvas().mapRenderer().setDestinationCrs(my_crs)

---

Simply change the 4326 CRS value in both cases to the Authority ID of your choice as shown in the image:

Answer 5

For me any above solution doesn't work. Maybe because I'm loading csv as vector layer, not a shape file. The only way I can make it work is:

crs = QgsCoordinateReferenceSystem(2180)
self.iface.mapCanvas().mapRenderer().setDestinationCrs(crs)
vlayer = QgsVectorLayer(filePath, "layer name", "ogr")
vlayer.setCrs(QgsCoordinateReferenceSystem(2180))

Answer 6

This answer describes how to avoid this dialog by specifying the CRS in the URL used to load the file into memory in the first place. So instead of passing the Shapefile path directly to addVectorLayer(), create a QgsVectorLayer with the appropriate URL and then call addMapLayer().

import urlparse
import urllib

baseuri = urlparse.urljoin('file:', urllib.pathname2url(self.shpFilePath))
uri = baseuri + "?crs=EPSG:4326"
vlayer = QgsVectorLayer(uri, "result", "memory")
QgsMapLayerRegistry.instance().addMapLayer(vlayer)